What are the permanently shadowed regions of the moon?

Unlocking the Moon’s Dark Secrets: What are Permanently Shadowed Regions?

Imagine spots on the Moon where the sun never shines. Sounds like something out of science fiction, right? Well, these places are real, and we call them Permanently Shadowed Regions, or PSRs for short. Think of them as the Moon’s hidden, icy treasure chests.

So, what makes these areas so special? It all boils down to the Moon’s slight tilt – just a baby wobble of about 1.5 degrees. Because of this, the bottoms of some craters, especially near the north and south poles, are in perpetual darkness. It’s like they’re wearing a never-ending nightcap!

Now, where exactly are we talking about? These shadowy nooks and crannies are clustered around the lunar poles. You’ll find them popping up at latitudes as low as 58 degrees. And get this: all those dark patches add up to a whopping 31,000 square kilometers! That’s a pretty big chunk of real estate hidden in the shadows, and more than half of it is on the Moon’s south side.

But here’s where it gets really interesting. Because they’re always in the dark, PSRs are unbelievably cold – we’re talking temperatures that can plunge to a bone-chilling 25 to 70 Kelvin (that’s -415°F to -334°F!). To put that in perspective, some of these spots are colder than Pluto! This extreme cold creates a perfect environment for trapping and preserving all sorts of volatile compounds, and that’s where the real magic happens: water ice.

Why all the fuss about frozen water? Well, if we ever want to set up a long-term base on the Moon, having a source of water is a game-changer. We’re not just talking about drinking water, though that’s important too! You can break water down into oxygen to breathe, and even turn it into rocket fuel. Talk about a lunar gas station!

We’ve got pretty solid evidence that water ice is hiding in these PSRs. Remember NASA’s LCROSS mission back in ’09? They basically crashed a rocket into one of these craters and saw water in the plume of debris that shot out. Pretty cool, huh? And the Lunar Reconnaissance Orbiter, or LRO, has been sniffing around up there too, finding clues that point to frozen water. One instrument, LAMP, uses ultraviolet light to peer into the darkness, while another, LEND, detects hydrogen, which is a key ingredient in water. Then, in 2018, the Moon Mineralogy Mapper (M3) sealed the deal, confirming actual water ice deposits in several PSRs.

Now, don’t go picturing giant skating rinks! The water ice is likely mixed in with the lunar soil, or regolith, in tiny pieces, or maybe even chemically bonded to minerals. Think of it like chocolate chips in a cookie, but instead of chocolate, it’s frozen water. Estimates say that, on average, there could be around 1.5% water mixed in with the top meter of lunar soil.

Of course, getting to this lunar ice cream isn’t going to be a walk in the park. These PSRs are tricky places to explore. It’s pitch black, which makes it hard for rovers to see where they’re going. The super-cold soil could be tough to drive on, and there’s always the risk of losing communication. Plus, solar storms can stir up the soil and create electrical charges, which could cause sparks and potentially vaporize some of that precious water ice!

Despite these challenges, we’re not giving up. NASA is taking PSRs so seriously that they’ve declared them “sensitive locations” to avoid messing them up. The ShadowCam, riding on the Korean Pathfinder Lunar Orbiter, is snapping super-detailed pictures of these dark regions. And the VIPER rover is gearing up to go on a hunt for water ice at the Moon’s south pole.

Remember Intuitive Machines’ IM-2 mission? They wanted to explore the Marston crater with a little hopper named Grace, but things didn’t quite go as planned. But don’t worry, there are plenty more missions on the horizon, including those under NASA’s Artemis program, which aims to send astronauts to these PSRs to study them up close and personal. Who knows, maybe one day we’ll be sipping lunar lemonade made with water from these permanently shadowed regions!